This is how not to do callbacks / resolveWithTimeout

gistfile1.m

- (void)netServiceBrowser:(NSNetServiceBrowser *)netServiceBrowser
           didFindService:(NSNetService *)netService
               moreComing:(BOOL)moreServicesComing {
    netService.delegate = self;
    [netService scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
    [netService resolveWithTimeout:3.0];
}